Savannah morning news. [volume] (Savannah) 1868-1887, 1887-03-24
IRON BRIDGES.
Opinions of u Number of Experts
Regarding Them


Regarding Them.
NEW YORK, March 19.-The following
expert opinions regarding bridge con-
struction suggested by recent railroad
disasters contain much that is new:
Capt. Samuel PrOhasco, assistant en-
gineer OF the Brooklyn bridge, said: 81
have read all the accounts OF tie Forest
Hills accident, but the facts given are so
meagre and contradictory that have not
| oeen able TO come to any definite con-
| cIusiOn. An iron bridge ought to be the
! best bridge in the world, and always is
when good metal, good workmanship and
| good construction areunited. What acct
dents remember Involving iron bridges
arose sometimes, but rarely, from pooC
metal, more frequently from inferior
! rolling or poor welding, and most OF all
from the train itself.
"In one case on the Reading railroad a
! car axle OF moving car broke, the truck
| was thrown down, and moved by the
| force OF the train fractured truss beam
and so wrecked the train. 1t Is said that
| long Earring will make iron as brittle as
! glass. While this seems true theoretically
| in certain cases, it is not borne out by
the facts. There are iron bridges over
fifty years old that have examined that
so far as any one can see are as good and
strong to-day as when they were first
erected.
Iron bridge building has undergone
great change for the better in the past
ten years. the business now being almost
monoDOhzed by Il few l8age corporations
and the quality OF the metal. workman
snip and construction being brought 20 a
nigh state OF perfection. | do not under
stand exactly what they mean by the
Forest Hils bridge not being anchored.
III they mean securely fastened TO the
aoutments, 50 that 1t could not move,
they are talking nonsense. Any iron
bridge must be allowed free room for the
contraction and expansion caused by the
change In temperature. Otherwise the
bridge would tear something loose some
where. On the Brooklyn bridge we have
three breaks in the metal work to allow
tor the notion"
Col. f. *. Hahn, Superintendent of the
New York Elevated railroad, SAID: II
have formed no opinion In regard to the
disaster. as | am in possession Of no facts.
L believe it advisable to anchor or rather
tasten iron bridges, and l do not believe
That iron beams weaEen with use from
vibration, AS respects the cause | can
only say that 1t would not be in my place
to comment upon IL except to remark that
the Boston and Providence is one OF the
best managed roads in this country"
d. L. Smith, prominent engineer and
railroad builder, said; II am unable to
determine whether the railroad accident
at Forest HILLS resulted from any imper-
lection IN the bridge or from something
That occurred to the tram. In very many
such cases the latter rather than the for
mer is the real cause OF the trouble. An
axle may break, a truck may get out of
order, connecting rod may be fractured
or nat wheel may slip, and any one
OF these may derail train and so crash
through a bridge. 1t looks. how
ever, as if there had been some
careless construction of the Forest
Hills yladucts in regard to the extremi-
ties OF the iron beams. These to-day, as
you may notice in the Fourth Avenue
Improvement in New York city, are SO
arranged as to provide for the ex-
pansion caused by hot weather, and at
the same time fastened securely so as to
prevent lateral motion, or spreading, and
aXial motion beyond the requisite ex-
pansiOn. This latter Is what The news
paper reports mean, l suppose. by an
| chOring. AS to weakening by long vbra-
ton, | do not believe that it amounts to
| anything"
Edward Wyman, Civil Engineer, said:
Judging from the later reports | have
read OF the Forest Hills accident, think
1t arose from hangers made OF inferior
iron or steel, or else of good metal con-
tanning large flaw or improperly welded.
Generally 1t is difficult to provide abso-
lutely against this contingency. Despite
every care one bad hanger may slip IN
among a lot, and If it occupies a respon-
sible position an accident may occur
Iron wears, / might say, forever. Col
umns on the old Gilbert Elevated that
were taken out after years Of use for fear
that they might be weakeped, proved
upon experiment to be as strong as on
the day they were put up. In fact. the
success OF the New York elevated roads,
as well as of the great iron bridges CT
the Old World and the new, show the
metal to be unrivaIed as material for all
kinds of bridges"
WILLIAM E. 5. FALEs.